change gear box and problem

[fawz66]

i have a cordoba 1998 1.4 ,i had a problem with the gear , so i change it , before in the fifth gear , i can speed up to 110km/h and the RPM will show 30000 rpm , now the speed is 90km/h for that rpm , and more the engine seems suufering and the sound in the engine is more loud
any idear before taking it to the workshop
regards

 

[Nath.]

Your new gearbox has different gear ratios. It's probably from a different model.

 

[fawz66]

yes . i think it is from polo classic 1998

 

[Shrako]

Did you check the gearbox serial numbers?

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